Straightedge



Patented Feb. 7, 1928.

UNITED STATES V.AILEREID PETER JACOB, 0F NEW YORK, N'. Y.

STRAIGHTEDGE.

Application led ctober 10, 1924. Serial No. 742,866.

This invention relates to a straight ed e and has particular referenceto a straig t edge for use in connection with drawing boards. I

The principal object of the invention is `to provide a straight edge:wherein the .cable and pulleys employed 1n devices of this nature, areconcealed within the body to prevent the cable from interfering with itso perations, and which also prevents any liability of the cable fronislipping o if the pulleys, which is a` serious objection in the straightedges heretofore constructed, and which further prevents the sagging ofthe cable on the surface of the drawing, causing obliteration of thelines as occurs Ain straight edges where the cable passesalong a rooveor opening `on its underside instead o passing through a conduitenclosed on all sides and which is the main feature of the presentinvention. y

.Another object of my present invention is. the provision of a straightedge for use in connection with a cable for lfacilitating the drawing ofparallel straight lines-.on large work; the said straight edge beingcharacterized b the capacity to receive and completely enc ose portionsof the cable whereby the straight edge may be moved or manipulatedwithout interference from the cable or any portion thereof.

To the attainment of the foregoing, the invention consists in theimprovement as hereinafter described and definitely claimed.

In the accompanying drawings, forming part of this specification pFigure 1 is a plan view showing my noyel straight edge as properlyarranged relative to a drawing board and a .cable associated with theboard.

Figure 2 is an enlarged elevation 'showing one end of the straight edgeand cable portions adjacent thereto.

Figure 3 is a longitudinal central section taken in the plane indicatedby the line 3-3 of Figure 1.

Figure`4 is an enlar ed cross-section taken in the plane indicate by theline 4-4 of Figure 1. Y

milar numerals of reference designate corresponding parts in all of theviews of the drawings. y

I show in Figure 1 a drawing board 1 together with a cable 2 and mynovel straight edge 3 which is characterized by an enclosed longitudinalcentral conduit 4 for the pasits ends to the drawing board l and islooped over guides 6 on the vdrawing board and is passed over thesheaves 5 and through the conduit 4 in therelation shown by full anddotted lines in Figure 1 and by full lines in Fi ures 2 and Manifest yby the manipulation of straight edge 3 constructed and arranged asdescribed parallel straight lines ma be made on large work with greatfacility; and it will be appreciated that b virtue of the cable beingextended throug i the conduit 4 of the straight edge 3, the cable offersno y projection on the surfacev of strai ht edge 3, and therefore thesaid strai lit e ge l3 may be conveniently handled an moved without anyliability of interference from the cable.

My novel straight edge 3 is preferably constructed in the manner shownin'Figiires 2, 3 and 4-i. e., the said straight edge comprises spacedlongitudinal and parallel sections 7 of wood between the opposedlongitudinal edges of which the before mentioned Vconduit 4 is formed,comparatively thin longitudinal edges of the sections 7 thin end plates11 of metal, and rivets 12 extending through and connecting the sections7, layers 8 and plates 11. It will also be observed that the sections 7and' the layers 8 are recessed at the ends of the straight edge for thehousing of the sheaves 5.

In theuse of my novel straight edge the cable 2 is arranged as shown inFigure 1, and in this con'nection it will be noted that the conduit 4lends itself to the crossing of the portions of the cable 2 within thestraight ed e 3 without the said cable ortions inter erring with thelateral ad]ust ment of the straight edge 3.

Notwithstanding the practical advantages ascribed to my novel straightedge, it will be manifest that the straight edge is simplel andinexpensive in construction and is well adapted to withstand the usageto which devices of this character are ordinarily subjected.

I have specifically described the construc-v tion embraced in thepreferred embodiment of my invention in order to impart an exactIunderstanding of said construction. I do not desire, however, to beunderstood as confining myself to the structure disclosed inasmuch as myinvention is defined by my claim within the scope of which changes instructure may be made without departure from my invention.

Having described my invention, what I claim and desire to secure byLetters-Patent, f

'A straight edge comprising longitudinal spaced sections, comparativelythin layers secured to the respective sides of and spacing said sectionsand cooperating with the same 1n formin a longitudinal conduit throughthe strag t edge, said sections being recessed at their ends, thinplates arranged et the outer sides of the respective ends of said th1nlayers, means connecting the sections, layers and lates, and sheavesmounted between the t in plates and disposed in the respective recessesand defining the ends of the said conduit.

0 In testimony whereof I hereby uiiix my signature.

ALFRED PETER JACOB.

